Black Rat and Brown Rat

Dominion, Volume 26, Issue 48, 19 November 1932, Page 16

Black Rat and Brown Rat

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THE house-rat, English rat, or black rat, with its bluish-black coat, has by no means disappeared from New Zealand. Although plentiful in and near Christchurch, its numbers in New Zealand have decreased, while the numbers of the larger brown rat, Norway rat, or common rat, have increased. These movements of rat populations have been noted in other countries, the black rat steadily giving way before the brown rat, in some cases almost suffering local extermination. The black rat’s plight, and its rival’s success, are more marked, perhaps, in England than anywhere else. Both these rats were accidentally introduced into England, in the .same way as, later, they were introduced into New Zealand, the black rat arriving first. The black rat’s original home, it is believed, was in the forests of India and of the Malay Peninsula. Probably about the time of the Norman Conquest, or of the first Crasade, it appeared in England. For hundreds of years, until the beginning of the eighteenth century, it was the only rat that infested English houses and shipping. It is blamed primarily for the outbreak of bubonic plague, called the Black Death. 267 years ago. It is primarily responsible for outbreaks of plague in India and in other warm countries at present. In New Zealand the position is that tbe brown rat is steadily increasing. while the black rat is decreasing. Many years have passed since brown rats pioneered New Zealand. They annoyed Mr. A. Reische, an early naturalist, when he camped in Chalky Inlet, in the .Southern Sounds: “The first night we camped on the mountains the grass country was swarming with rats. They gnawed our boots, which we kept with us in the tent. When we had supper near the fire they came behind us and nibbled the bones we placed for the dogs. In the hut they made so much noise at night that I could hardly sleep. They ran over us in bed, knocked articles from the shelves and gnawed provision cases. They dug up and carried away potatoes planted in the garden. I had birdskins in a drying hut, hung on thin wires, and well-poisoned. Rats climbed the rafters, jumped down on the skins and spoilt several. 1 had skeletons of birds hanging on a thin wire, twelve feet high and twenty feet long; for three weeks they tried in vain to walk the tight-rooe. and at last succeeded. Then they wound their tails

J. Drummond,

F.L.S., y.Z.S., for “The Dominion.")

around the flax like opossums, slid down nearly two feet, and gnawed the bones aud spoilt the skeletons. They amused me by disturbing my companion, Mr. Rimmer. He sleeps so soundly that nothing wakes him; even when I flred the gun at the rats in the hut he did not hear it; but on the mountains they took a fancy for his hair, and by biting it away they awakened him three times in one night.”

The black rat may have been brought to New Zealand on Captain Cook’s vessels 162 years ago. In any case, in the early days of settlement, before the brown rat spread widely in the colony, it was very plentiful, much more so than at present. The Hon. G. M. Thomson records that it moved about the country in vast armies. Settlers, bushfellers and sawmill hands described invasions by countless swarms of black rats, which climbed everywhere and devoured everything of a vegetable nature. Ninety-two years ago, Messrs. Dodd and Davis, of Sydney, raised crops on thirty acres at Riccarton, near Christchurch. Black rats attacked the stores so vigorously that the farm was abandoned. The Maori rat, kiore, seems to be identical with the native rat of Polynesia. There Is a belief that originally New Zealand was a ratless country and that the Maoris brought their kiore with them at the time o their migration from Tahiti, 500 or 600 years ago, using it for food. It is rarer than the black rat. but there is not sufficient evidence to report that it is extinct in New Zealand. Its coat is greyish-white on top, paler below. It is smaller than the brown rat, but it has a longer tail, which is the same length as its head and body'; and its ears are large and round. Before Europeans came to New Zealand, Maoris caught their rats in traps and snares, and roasted, steamed or potted them. The rat-catching season was opened ceremoniously, andffhe expert rat-catchers were subjected temporarily to strict tapu rites. For a long time the black rat, in zoological literature, was Mus rattus, the brown rat was Mus decumanus, and tbe Maori rat was Mus Maorlum. Changes in zoological nomenclature give the black rat the title Rattus rattus, the brown rat is Rattus norvegicus, and the Maori rat is Rattus exulans. The mouse, which came from the Old Country, is Mus musculus.